JP6777845B2 - Prober and probe contact method - Google Patents

Description

The present invention relates to a prober and probe contact method for inspecting electrical characteristics of a plurality of semiconductor devices (chips) formed on a semiconductor wafer, and in particular, a multi-stage prober and probe contact provided with a plurality of measuring units. Regarding the method.

The semiconductor manufacturing process has a large number of steps, and various inspections are performed in various manufacturing processes in order to guarantee quality and improve yield. For example, when a plurality of chips of a semiconductor device are formed on a semiconductor wafer, the electrode pads of the semiconductor device of each chip are connected to a test head, a power supply and a test signal are supplied from the test head, and the semiconductor device is output. Wafer level inspection is performed by measuring the signal with a test head and electrically inspecting whether it operates normally.

After wafer level inspection, the wafer is affixed to the frame and cut into individual chips with a die. As for each of the cut chips, only the chips confirmed to operate normally are packaged in the next assembly step, and the malfunctioning chips are excluded from the assembly step. In addition, the final packaged product is inspected for shipment.

Wafer level inspection is performed using a prober that brings the probe into contact with the electrode pads of each chip on the wafer. The probe is electrically connected to the terminal of the test head, and power and test signals are supplied from the test head to each chip via the probe, and the output signal from each chip is detected by the test head to see if it operates normally. To measure.

In the semiconductor manufacturing process, wafers are being made larger and further miniaturized (integrated) in order to reduce manufacturing costs, and the number of chips formed on one wafer is extremely large. ing. Along with this, the time required for inspecting one wafer with a prober has become longer, and improvement in throughput is required. Therefore, in order to improve the throughput, multiprobing is performed in which a large number of probes are provided so that a plurality of chips can be inspected at the same time. In recent years, the number of chips to be inspected at the same time has been increasing, and attempts have been made to inspect all the chips on the wafer at the same time. Therefore, the tolerance for alignment of the electrode pad and the probe in contact with each other is small, and it is required to improve the positioning accuracy of movement in the prober.

On the other hand, the simplest way to increase the throughput is to increase the number of probers, but increasing the number of probers causes a problem that the installation area of the probers in the production line also increases. In addition, if the number of probers is increased, the equipment cost will increase accordingly. Therefore, it is required to increase the throughput by suppressing the increase in the installation area and the increase in the equipment cost.

Against this background, for example, Patent Document 1 proposes a test apparatus (multi-stage prober) including a plurality of measuring units. In this test device, an alignment device that aligns the wafer and the probe card relative to each other is configured to be able to move between the measuring units.

However, in the test apparatus described in Patent Document 1, although space saving and cost reduction can be achieved by sharing the alignment apparatus in each measuring unit, there are the following problems.

That is, when the moving distance of the alignment device becomes long, the moving mechanism for moving the alignment device to each measurement unit and the support member (frame) to which the moving mechanism is attached are affected by the weight of the alignment device, thermal expansion or contraction. As a result, distortion is likely to occur, which causes a decrease in the positional accuracy of the alignment device moved to each measuring unit. Therefore, it takes time to detect the positions of the electrode pads and probes on the wafer by using the imaging means, and as a result, the alignment operation takes time and the throughput becomes slow.

On the other hand, the applicant of the present application has proposed a prober that improves the above problem in a multi-stage prober provided with a plurality of measuring units (see Patent Document 2). In this prober, the alignment device moved to each measurement unit is positioned and fixed by the positioning and fixing device, so that the throughput can be reduced by suppressing the increase in the installation area and the device cost while maintaining the accuracy of the moving position of the alignment device. Can be improved.

Japanese Unexamined Patent Publication No. 2010-186998 Japanese Unexamined Patent Publication No. 2014-192218

By the way, in the conventional prober described in Patent Document 1 and Patent Document 2, a vacuum suction method for holding the wafer chuck on the probe card side is adopted. In this vacuum suction method, the internal space (sealed space) formed between the wafer chuck and the probe card is depressurized by a decompression means, and the wafer chuck is attracted to the probe card side, so that the electrode pad and the probe on the wafer are used. A contact operation is performed in which the and is in contact with each other.

However, in the contact operation by the vacuum suction method, it is difficult to accurately control the moving distance and moving speed of the wafer chuck, and the contact operation tends to vary. Further, since the moving speed when pulling the wafer chuck toward the probe side is slow, the oxide film (insulator) on the electrode pad cannot be removed even if the probe comes into contact with the electrode pad on the wafer, and the wafer is on the wafer. There is a problem that it is difficult to achieve good contact between the electrode pad and the probe.

The present invention has been made in view of such circumstances, and provides a prober and probe contact method capable of realizing good contact between an electrode pad on a wafer and a probe in a multi-stage prober. The purpose is.

In order to achieve the above object, the prober according to the first aspect of the present invention is provided so as to face the wafer chuck and the wafer chuck, and has a probe at a position corresponding to each electrode pad of the wafer. It has a probe card, an annular seal member provided on the wafer chuck and formed so as to surround the wafer held by the wafer chuck, and a wafer chuck fixing portion for detachably fixing the wafer chuck. The internal space formed by the probe card, the wafer chuck, and the sealing member is depressurized when the wafer chuck is moved toward the probe card by the mechanical lifting means for raising and lowering the wafer chuck fixed to the probe card. The decompression means and the elevating control means for controlling the mechanical elevating means to move the wafer chuck so as to bring the probe into contact with the electrode pad in the overdrive state, and the probe contacted the electrode pad in the overdrive state. After that, a decompression control means for controlling the decompression means so that the wafer chuck is attracted to the probe card by decompression of the internal space is provided.

In the first aspect, the prober according to the second aspect of the present invention determines the height position of the wafer chuck before the probe contacts the electrode pad when the wafer chuck is moved toward the probe card by the mechanical elevating means. The position immediately before the contact is set, the height position when the probe contacts the electrode pad is set as the contact position, and the height position of the wafer chuck when the probe contacts the electrode pad in the overdrive state during wafer inspection is the final overdrive position. When the position is set and the height position of the wafer chuck between the contact position and the final position of the overdrive is set to the intermediate position of the overdrive, the elevating control means moves the wafer chuck from the standby position to the position immediately before the contact at the first moving speed. The mechanical elevating means is controlled so as to move the wafer chuck from the position immediately before the contact to the intermediate position of the overdrive at a second moving speed slower than the first moving speed, and the decompression control means is the height position of the wafer chuck. Controls the decompression means so that is the final position of the overdrive.

In the prober according to the third aspect of the present invention, in the second aspect, the elevating control means moves the wafer chuck from the standby position to the position immediately before the contact at the first moving speed, and then temporarily stops the movement of the wafer chuck. Then, the wafer chuck is moved from the position immediately before the contact to the position during the overdrive at the second moving speed.

In the prober according to the fourth aspect of the present invention, in the second or third aspect, the elevating control means mechanically elevates and reciprocates the wafer chuck a plurality of times between the position immediately before the contact and the position during the overdrive. Control the means.

In the first aspect, the prober according to the fifth aspect of the present invention determines the height position of the wafer chuck before the probe contacts the electrode pad when the wafer chuck is moved toward the probe card by the mechanical elevating means. The position immediately before the contact is set, the height position when the probe contacts the electrode pad is set as the contact position, and the height position of the wafer chuck when the probe contacts the electrode pad in the overdrive state during wafer inspection is the final overdrive position. When the position is set and the height position of the wafer chuck between the contact position and the final position of the overdrive is set to the intermediate position of the overdrive, the elevating control means moves the wafer chuck from the standby position to the position immediately before the contact at the first moving speed. The mechanical lifting means is controlled so that the wafer chuck is moved from the position immediately before the contact to the final position of the overdrive at a second moving speed slower than the first moving speed, and the decompression control means is the height position of the wafer chuck. Controls the decompression means so that is the final position of the overdrive.

In the fifth aspect of the prober according to the sixth aspect of the present invention, the elevating control means moves the wafer chuck to the final overdrive position and then moves the wafer chuck to the overdrive intermediate position. To control.

In the prober according to the seventh aspect of the present invention, in any one of the second to sixth aspects, the decompression control means sets the height of the wafer chuck between the final overdrive position and the intermediate overdrive position. The decompression means is controlled so as to move back and forth multiple times.

In any one of the second to seventh aspects, the prober according to the eighth aspect of the present invention has a wafer chuck fixing portion at a second timing later than the first timing at which the internal space is depressurized by the decompression means. The wafer chuck is provided with a timing control means for releasing the fixing of the wafer chuck.

The probe contact method according to the ninth aspect of the present invention includes a wafer chuck that holds a wafer, a probe card that is provided so as to face the wafer chuck and has a probe at a position corresponding to each electrode pad of the wafer, and a wafer chuck. A wafer chuck provided in the above and having an annular sealing member formed so as to surround the wafer held by the wafer chuck and a wafer chuck fixing portion for detachably fixing the wafer chuck, and fixed to the wafer chuck fixing portion. A mechanical lifting means for raising and lowering the wafer, and a depressurizing means for reducing the internal space formed by the probe card, the wafer chuck, and the sealing member when the wafer chuck is moved toward the probe card by the mechanical lifting means. This is a probe contact method in the prober provided, and when the wafer chuck is moved toward the probe card by mechanical lifting means, the height position of the wafer chuck before the probe contacts the electrode pad is set as the position immediately before the contact, and the probe is provided. The height position when the probe contacts the electrode pad is the contact position, and the height position of the wafer chuck when the probe contacts the electrode pad in the overdrive state during wafer inspection is the final overdrive position. When the height position of the wafer chuck with respect to the final position of the overdrive is set to the intermediate position of the overdrive, the first moving step of moving the wafer chuck from the standby position to the position immediately before the contact at the first moving speed by the mechanical elevating means. The second moving step of moving the wafer chuck from the position immediately before the contact to the intermediate position of the overdrive at a second moving speed slower than the first moving speed by the mechanical lifting means, and the height position of the wafer chuck are overdriven by the decompression means. A decompression step of depressurizing the internal space so as to be the final position is provided.

The probe contact method according to the tenth aspect of the present invention includes, in the ninth aspect, a stopping step of temporarily stopping the movement of the wafer chuck between the first moving step and the second moving step.

In the probe contact method according to the eleventh aspect of the present invention, in the ninth or tenth aspect, the second moving step reciprocates the wafer chuck a plurality of times between the position immediately before the contact and the position during the overdrive.

The probe contact method according to the twelfth aspect of the present invention includes a wafer chuck that holds a wafer, a probe card that is provided so as to face the wafer chuck and has a probe at a position corresponding to each electrode pad of the wafer, and a wafer chuck. A wafer chuck provided in the above and having an annular sealing member formed so as to surround the wafer held by the wafer chuck and a wafer chuck fixing portion for detachably fixing the wafer chuck, and fixed to the wafer chuck fixing portion. A mechanical lifting means for raising and lowering the wafer, and a depressurizing means for reducing the internal space formed by the probe card, the wafer chuck, and the sealing member when the wafer chuck is moved toward the probe card by the mechanical lifting means. This is a probe contact method in the prober provided, and when the wafer chuck is moved toward the probe card by mechanical lifting means, the height position of the wafer chuck before the probe contacts the electrode pad is set as the position immediately before the contact, and the probe is provided. The height position when the probe contacts the electrode pad is the contact position, and the height position of the wafer chuck when the probe contacts the electrode pad in the overdrive state during wafer inspection is the final overdrive position. When the height position of the wafer chuck with respect to the final position of the overdrive is set to the intermediate position of the overdrive, the first moving step of moving the wafer chuck from the standby position to the position immediately before the contact at the first moving speed by the mechanical elevating means. The second moving step of moving the wafer chuck from the position immediately before the contact to the final position of the overdrive at a second moving speed slower than the first moving speed by the mechanical lifting means, and the overdrive of the wafer chuck height position by the decompression means. A decompression step of depressurizing the internal space so as to be the final position is provided.

In the probe contact method according to the thirteenth aspect of the present invention, in the twelfth aspect, in the second moving step, after the wafer chuck is moved to the final position of the overdrive, the wafer chuck is moved to the intermediate position of the overdrive by mechanical elevating means. Move.

In the probe contact method according to the 14th aspect of the present invention, in any one of the 9th to 13th aspects, in the decompression step, the height of the wafer chuck is overdriven by the decompression means to the final position and the intermediate position of the overdrive. Move back and forth multiple times to and from.

In the probe contact method according to the fifteenth aspect of the present invention, in any one of the ninth to thirteenth aspects, the wafer chuck is performed at a second timing later than the first timing at which the internal space is depressurized by the decompression means. A timing control step for releasing the fixing of the wafer chuck by the fixing portion is provided.

According to the present invention, in a multi-stage prober, good contact can be achieved between the electrode pad and the probe on the wafer.

External view showing the overall configuration of the prober according to the embodiment of the present invention. Top view showing the whole structure of the prober which concerns on embodiment of this invention Schematic diagram showing the configuration of the measurement unit in the prober according to the embodiment of the present invention. Schematic diagram showing the configuration of the measuring unit in the measuring unit shown in FIG. Functional block diagram showing the configuration of the prober control device according to the embodiment of the present invention. A flowchart showing a contact operation in the prober according to the embodiment of the present invention. The figure for demonstrating the contact operation in the prober which concerns on embodiment of this invention. The figure for demonstrating the contact operation in the prober which concerns on embodiment of this invention. The figure for demonstrating the contact operation in the prober which concerns on embodiment of this invention. The figure for demonstrating the contact operation in the prober which concerns on embodiment of this invention. The figure for demonstrating the contact operation in the prober which concerns on embodiment of this invention. The figure for demonstrating the contact operation in the prober which concerns on embodiment of this invention. Timing chart of contact operation in the prober according to the embodiment of the present invention The figure which showed the 1st operation example of the contact operation in the prober which concerns on embodiment of this invention. The figure which showed the 2nd operation example of the contact operation in the prober which concerns on embodiment of this invention. The figure which showed the 3rd operation example of the contact operation in the prober which concerns on embodiment of this invention. The figure which showed the 4th operation example of the contact operation in the prober which concerns on embodiment of this invention. The figure which showed the 5th operation example of the contact operation in the prober which concerns on embodiment of this invention. Schematic diagram showing how the oxide film on the electrode pad is removed by the probe in the fifth operation example of the contact operation. The figure which showed the sixth operation example of the contact operation in the prober which concerns on embodiment of this invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

1 and 2 are an external view and a plan view showing the overall configuration of the prober according to the embodiment of the present invention.

As shown in FIGS. 1 and 2, the prober 10 of the present embodiment is arranged adjacent to the loader unit 14 for supplying and collecting the wafer W to be inspected (see FIG. 4) and the loader unit 14, and a plurality of measurements are performed. It includes a measuring unit 12 having a unit 16. The measuring unit 12 has a plurality of measuring units 16, and when the wafer W is supplied from the loader unit 14 to each measuring unit 16, each measuring unit 16 inspects the electrical characteristics of each chip of the wafer W. (Wafer level inspection) is performed. Then, the wafer W inspected by each measuring unit 16 is collected by the loader unit 14. The prober 10 also includes an operation panel 22, a control device (see FIG. 5) described later, and the like.

The loader unit 14 has a load port 18 on which the wafer cassette 20 is placed, and a transfer unit 24 that conveys the wafer W between each measurement unit 16 of the measurement unit 12 and the wafer cassette 20. The transport unit 24 is provided with a transport unit drive mechanism (not shown), and is configured to be movable in the X and Z directions and to be rotatable in the θ direction (around the Z direction). Further, the transport unit 24 includes a transport arm 26 that is vertically expanded and contracted back and forth by the transport unit drive mechanism. A suction pad (not shown) is provided on the upper surface of the transfer arm 26, and the transfer arm 26 holds the wafer W by vacuum suctioning the back surface of the wafer W with the suction pad. As a result, the wafer W in the wafer cassette 20 is taken out by the transfer arm 26 of the transfer unit 24 and transferred to each measurement unit 16 of the measurement unit 12 while being held on the upper surface thereof. Further, the inspected wafer W whose inspection has been completed is returned from each measuring unit 16 to the wafer cassette 20 by the reverse route.

FIG. 3 is a schematic view showing the configuration of a measurement unit in the prober according to the embodiment of the present invention. FIG. 4 is a schematic view showing the configuration of the measuring unit in the measuring unit shown in FIG.

As shown in FIG. 3, the measuring unit 12 has a laminated structure (multi-stage structure) in which a plurality of measuring units 16 are laminated in a multi-stage shape, and each measuring unit 16 has 2 in the X direction and the Z direction. It is arranged dimensionally. In the present embodiment, as an example, four measuring units 16 in the X direction are stacked in three stages in the Z direction.

The measurement unit 12 includes a housing (not shown) having a grid shape in which a plurality of frames are combined in a grid pattern. This housing is formed by combining a plurality of frames extending in the X direction, the Y direction, and the Z direction in a grid pattern, and each space portion formed by these frames is a component of the measurement unit 16. Is placed.

Each measuring unit 16 has the same configuration, and includes a head stage 30, a probe card 32, and a wafer chuck 34, as shown in FIG. Further, each measuring unit 16 is provided with a test head (not shown). The test head is supported above the head stage 30 by a test head holding portion (not shown).

The head stage 30 is supported by a frame member (not shown) that constitutes a part of the housing, and the probe card 32 is detachably attached and fixed. The probe card 32 mounted and fixed to the head stage 30 is provided so as to face the wafer holding surface 34a of the wafer chuck 34. The probe card 32 is replaced according to the wafer W (device) to be inspected.

The probe card 32 is provided with a plurality of probes 36 such as a cantilever and a spring pin, which are arranged corresponding to the positions of the electrode pads of each chip of the wafer W to be inspected. Each probe 36 is electrically connected to a terminal of a test head (not shown), a power supply and a test signal are supplied from the test head to each chip via each probe 36, and an output signal from each chip is detected by the test head. And measure whether it works normally. Since the connection configuration between the probe card 32 and the test head is not a main part of the present invention, detailed description thereof will be omitted.

The probe 36 has a spring property, and by raising the contact point from the tip position of the probe 36, the probe 36 comes into contact with the electrode pad at a predetermined contact pressure. Further, when the electrode pad is in contact with the probe 36 in an overdrive state during an electrical inspection, the tip of the probe 36 sinks into the surface of the electrode pad and forms needle marks on the surface of the electrode pad. It is designed to do. The overdrive means that the electrode pad and the probe 36 are surely in contact with each other in consideration of the inclination of the wafer W and the arrangement surface of the tip of the probe 36 and the variation in the tip position of the probe 36. This refers to a state in which the surface of the electrode pad, that is, the wafer W, is raised by a distance α to a position higher than the tip position of 36. Further, the amount of movement that further raises the surface of the wafer W from the tip position of the probe 36 (corresponding to the contact position described later), that is, the distance α is referred to as an overdrive amount.

The wafer chuck 34 sucks and fixes the wafer W by vacuum suction or the like. The wafer chuck 34 has a wafer holding surface 34a on which the wafer W to be inspected is placed, and the wafer holding surface 34a is provided with a plurality of suction ports 40 (only one is shown in FIG. 4). The suction port 40 is connected to a suction device (vacuum source) 44 such as a vacuum pump via a suction path 42 formed inside the wafer chuck 34. A wafer suction solenoid valve 46 is provided in the suction path connecting the suction device 44 and the suction path 42. The wafer adsorption solenoid valve 46 is controlled by the wafer adsorption solenoid valve control unit 110 (see FIG. 5).

On the outer side of the wafer holding surface 34a of the wafer chuck 34, an elastic ring-shaped sealing member (chuck sealing rubber) 48 formed so as to surround the wafer W held by the wafer holding surface 34a is provided. When the wafer chuck 34 is moved (raised) toward the probe card 32 by the Z-axis moving / rotating portion 72 described later, the ring-shaped sealing member 48 comes into contact with the lower surface of the head stage 30, so that the wafer chuck 34, An internal space S (see FIGS. 7B to 7F) surrounded by the probe card 32 and the ring-shaped sealing member 48 is formed. The ring-shaped seal member 48 is an example of the annular seal member of the present invention.

The head stage 30 is provided with a suction port 50 for reducing the pressure in the internal space S formed between the probe card 32 and the wafer chuck 34. The suction port 50 is connected to the suction device 44 via a suction path 52 formed inside the head stage 30. A vacuum electropneumatic regulator 54 is provided in the suction path connecting the suction device 44 and the suction path 52. The vacuum electropneumatic regulator 54 is a control valve that adjusts the internal pressure (vacuum degree) of the internal space S. The vacuum electropneumatic regulator 54 is controlled by a suction control unit 114 (see FIG. 5), which will be described later. The suction device 44 and the vacuum electropneumatic regulator 54 are examples of the depressurizing means of the present invention.

The wafer chuck 34 is provided with a communication passage 56 that communicates between the internal space S and the external space. One end of the communication passage 56 is open to a region of the wafer holding surface 34a of the wafer chuck 34 near the outer periphery where the wafer W is not placed, and the other end of the communication passage 56 is open to the side surface of the wafer chuck 34. A shutter means 58 capable of opening and blocking the communication passage 56 is provided on the side surface of the wafer chuck 34. When the shutter means 58 is opened, the communication passage 56 is in an open state, and the internal space S is in a state of communicating with the external space via the communication passage 56 (communication state). On the other hand, when the shutter means 58 is closed, the communication passage 56 is in a cutoff state, and the internal space S is in a state of not communicating with the external space (non-communication state). The shutter means 58 is controlled by the shutter control unit 116 (see FIG. 5), which will be described later. Since a known configuration is applied to the shutter means 58, detailed description thereof will be omitted.

In the present embodiment, as an example, a communication state (non-sealed state) and a non-communication state (sealed state) in which the internal space S is communicated with the external space by the communication passage 56 and the shutter means 58 provided in the wafer chuck 34. Although the configuration can be selectively switched between the two, instead of the configuration of the present embodiment, for example, the head stage 30 or the probe card 32 may be provided with a communication passage and a shutter means.

Inside the wafer chuck 34, a heating / cooling source is provided so that the wafer W to be inspected can be inspected for electrical characteristics in a high temperature state (for example, 150 ° C. at the maximum) or in a low temperature state (for example, −40 ° C. at the minimum). A heating / cooling mechanism (not shown) is provided. As the heating / cooling mechanism, a known appropriate heater / cooler can be adopted. For example, a dual layer structure of a heating layer of a surface heater and a cooling layer provided with a cooling fluid passage, or heat. Various devices such as a single-layer heating / cooling device in which a cooling tube around which a heater is wound are embedded in the conductor can be considered. Further, instead of electric heating, a thermal fluid may be circulated, or a Peltier element may be used.

The wafer chuck 34 is detachably supported and fixed to an alignment device 70 described later. The alignment device 70 moves the wafer chuck 34 in the X, Y, Z, and θ directions to align the wafer W held by the wafer chuck 34 with the probe card 32 relative to each other.

The alignment device 70 detachably supports and fixes the wafer chuck 34, moves the wafer chuck 34 in the Z-axis direction, and rotates in the θ direction with the Z-axis as the rotation center, and the Z-axis movement / rotating portion 72 and the Z-axis movement. An X-axis moving table 74 that supports the rotating portion 72 and moves in the X-axis direction, and a Y-axis moving table 76 that supports the X-axis moving table 74 and moves in the Y-axis direction are provided.

The Z-axis moving / rotating unit 72, the X-axis moving table 74, and the Y-axis moving table 76 are each configured to move or rotate the wafer chuck 34 in a predetermined direction by a mechanical drive mechanism including at least a motor. To. The mechanical drive mechanism includes, for example, a ball screw drive mechanism in which a servomotor and a ball screw are combined. Further, the structure is not limited to the ball screw drive mechanism, and may be composed of a linear motor drive mechanism, a belt drive mechanism, or the like. The Z-axis moving / rotating unit 72, the X-axis moving table 74, and the Y-axis moving table 76 are configured so that the moving distance, moving direction, moving speed, and acceleration of the wafer chuck 34 can be changed by each control unit described later. ing. Specifically, the present embodiment has the following configuration.

The Z-axis moving / rotating unit 72 is an example of the mechanical lifting means of the present invention, and is a Z-axis drive motor 122 (for example, a stepping motor, a servomotor, a linear motor, etc.) for moving the wafer chuck 34 in the Z-axis direction. (See FIG. 5) and a Z-axis encoder (for example, a rotary encoder, a linear scale, etc.) (not shown) for detecting the moving distance of the wafer chuck 34 in the Z-axis direction. The Z-axis drive motor 122 is controlled based on a motor control signal from the Z-axis movement control unit 106 (see FIG. 5) described later, and drives the wafer chuck 34 to move to a target position at a desired movement speed or acceleration. .. Further, the Z-axis encoder outputs an encoder signal according to the movement of the wafer chuck 34.

Further, the Z-axis moving / rotating unit 72 includes a rotary drive motor 124 (for example, a stepping motor, a servomotor, a linear motor, etc.) for rotating the wafer chuck 34 in the θ direction (see FIG. 5) and the wafer chuck 34. It is provided with a rotation encoder (for example, a rotary encoder or the like) (not shown) for detecting a rotation angle in the θ direction. The rotation drive motor 124 is controlled based on a motor control signal from the θ rotation control unit 108 (see FIG. 5), which will be described later, and drives the wafer chuck 34 to move to a target position at a desired rotation speed or acceleration. Further, the rotary encoder outputs an encoder signal according to the rotation of the wafer chuck 34.

The X-axis moving table 74 includes an X-axis drive motor 118 (for example, a stepping motor, a servomotor, a linear motor, etc.) for moving the wafer chuck 34 in the X-axis direction (see FIG. 5) and an X-axis of the wafer chuck 34. It is equipped with an X-axis encoder (for example, a rotary encoder, a linear scale, etc.) (not shown) for detecting a moving distance in a direction. The X-axis drive motor 118 is controlled based on a motor control signal from the X-axis movement control unit 102 (see FIG. 5) described later, and drives the wafer chuck 34 to move to a target position at a desired movement speed or acceleration. .. Further, the X-axis encoder outputs an encoder signal according to the movement of the wafer chuck 34.

The Y-axis moving table 76 includes a Y-axis drive motor 120 (for example, a stepping motor, a servomotor, a linear motor, etc.) for moving the wafer chuck 34 in the Y-axis direction (see FIG. 5) and a Y-axis of the wafer chuck 34. It is equipped with a Y-axis encoder (for example, a rotary encoder, a linear scale, etc.) (not shown) for detecting a moving distance in a direction. The Y-axis drive motor 120 is controlled based on a motor control signal from the Y-axis movement control unit 104 (see FIG. 5) described later, and drives the wafer chuck 34 to move to a target position at a desired movement speed or acceleration. .. Further, the Y-axis encoder outputs an encoder signal according to the movement of the wafer chuck 34.

The alignment device 70 is provided for each stage (see FIG. 3), and is configured to be mutually movable between a plurality of measuring units 16 arranged in each stage by an alignment device drive mechanism (not shown). .. That is, the alignment device 70 is shared among a plurality of (four in this example) measuring units 16 arranged in the same stage, and moves between the plurality of measuring units 16 arranged in the same stage. To do. The alignment device 70 moved to each measurement unit 16 is fixed in a predetermined position by a positioning and fixing device (not shown), and the wafer chuck 34 is moved in the X, Y, Z, and θ directions and held by the wafer chuck 34. Relative alignment between the wafer W and the probe card 32 is performed. Although not shown, the alignment device 70 includes a needle position detection camera and a needle position detection camera in order to detect the relative positional relationship between the electrode pad of each chip of the wafer W held by the wafer chuck 34 and the probe 36. It is equipped with a wafer alignment camera. Further, the alignment device drive mechanism is composed of a mechanical drive mechanism such as a ball screw drive mechanism, a linear motor drive mechanism, and a belt drive mechanism.

A ring-shaped sealing member (Z-axis sealing rubber) 78 having elasticity formed in an annular shape along the outer circumference is provided on the wafer chuck supporting surface 72a of the Z-axis moving / rotating portion 72 forming the upper surface of the alignment device 70. Further, a suction port 80 is provided inside the ring-shaped seal member 78 of the wafer chuck support surface 72a. The suction port 80 is connected to the suction device 44 via a suction path 82 formed inside the wafer chuck 34. A chuck fixing solenoid valve 84 and a throttle valve 86 are provided in order from the suction device 44 side in the suction path connecting the suction device 44 and the suction path 82. The chuck fixing solenoid valve 84 is controlled by the chuck fixing solenoid valve control unit 112 (see FIG. 5), which will be described later. The wafer chuck support surface 72a of the Z-axis moving / rotating portion 72 is an example of the wafer chuck fixing portion of the present invention. Further, the suction port 80 provided on the wafer chuck support surface 72a is an example of a component of the wafer chuck fixing portion.

A positioning pin 88 is provided on the outside of the ring-shaped seal member 78 of the wafer chuck support surface 72a of the Z-axis moving / rotating portion 72 so that the relative positional relationship of the wafer chuck 34 with respect to the alignment device 70 is always constant. ing. The positioning pins 88 are provided at three positions at equal intervals along the circumferential direction centered on the central axis of the wafer chuck 34 (only two are shown in FIG. 4). A V block 90, which is a positioning member, is provided on the lower surface of the wafer chuck 34 at a position corresponding to each positioning pin 88. When the wafer chuck 34 is attracted and fixed by vacuum suction, the corresponding positioning pins 88 are engaged in the V grooves of each V block 90 in the horizontal direction (X direction and Y direction) of the wafer chuck 34. ) Is restrained, and the alignment device 70 and the wafer chuck 34 are relatively positioned.

In the present embodiment, the alignment device 70 sucks and fixes the wafer chuck 34 by vacuum suction or the like, but if the wafer chuck 34 can be fixed, a fixing means other than vacuum suction may be used, for example, mechanically. It may be fixed by means or the like.

FIG. 5 is a functional block diagram showing a configuration of a prober control device according to an embodiment of the present invention.

As shown in FIG. 5, the control device of the prober 10 of the present embodiment includes the overall control unit 100, the X-axis movement control unit 102, the Y-axis movement control unit 104, the Z-axis movement control unit 106, and the θ rotation control unit 108. It includes a wafer suction solenoid valve control unit 110, a chuck fixing solenoid valve control unit 112, a suction control unit 114, a shutter control unit 116, and the like.

The overall control unit 100 comprehensively controls each unit constituting the prober 10. Specifically, the overall control unit 100 controls an operation (contact operation) of bringing the electrode pads of each chip of the wafer W to be inspected into contact with each probe 36 of the probe card 32. Further, in addition to the contact operation, the overall control unit 100 controls the movement of the alignment device 70 to be moved between the measurement units 16 and the operation of the wafer level inspection by the test head. Since the control other than the contact operation is not a main part of the present invention, detailed description thereof will be omitted.

The X-axis movement control unit 102 moves the X-axis moving table 74 in the X-axis direction by controlling the drive of the X-axis drive motor 118 provided on the X-axis moving table 74, thereby moving the wafer chuck 34 in the X-axis direction. Move to. The Y-axis movement control unit 104 controls the drive of the Y-axis drive motor 120 provided on the Y-axis movement base 76 to move the Y-axis movement base 76 in the Y-axis direction, thereby moving the wafer chuck 34 in the Y-axis direction. Move to. The Z-axis movement control unit 106 raises and lowers the Z-axis movement / rotation unit 72 by controlling the drive of the Z-axis drive motor 122 provided in the Z-axis movement / rotation unit 72, thereby moving the wafer chuck 34 in the Z-axis direction. Move to. The θ rotation control unit 108 rotates the Z-axis movement / rotation unit 72 in the θ direction by controlling the drive of the rotation drive motor 124 provided in the Z-axis movement / rotation unit 72, thereby rotating the wafer chuck 34 in the θ direction. Rotate to. The Z-axis movement control unit 106 is an example of the elevating control means of the present invention.

The wafer suction solenoid valve control unit 110 adjusts the suction pressure by the suction port 40 by controlling ON / OFF (open / close) of the wafer suction solenoid valve 46, and fixes / fixes the wafer W to the wafer chuck 34. Selectively switch between non-fixed.

The chuck fixing solenoid valve control unit 112 adjusts the suction pressure by the suction port 80 by controlling ON / OFF (opening / closing) of the chuck fixing solenoid valve 84, and the wafer with respect to the Z-axis moving / rotating unit 72. The chuck 34 is selectively switched between fixed and non-fixed.

The suction control unit 114 adjusts the internal pressure (vacuum degree) of the internal space S steplessly by controlling the operation of the vacuum electropneumatic regulator 54. The suction control unit 114 is an example of the suction control means of the present invention.

The shutter control unit 116 selectively switches between opening and closing of the communication passage 56 communicating between the internal space S and the external space by controlling the opening and closing of the shutter means 58.

Next, the contact operation in the prober 10 according to the present embodiment will be described with reference to FIGS. 6, 7A to 7F, and FIG. This operation is performed under the control of the overall control unit 100. Hereinafter, the outline of the contact operation in the prober 10 according to the present embodiment will be described, and then the detailed operation will be described.

FIG. 6 is a flowchart showing a contact operation in the prober according to the embodiment of the present invention. 7A-7F are diagrams for explaining the contact operation in the prober according to the embodiment of the present invention. FIG. 8 is a timing chart showing the contact operation in the prober according to the embodiment of the present invention. The time width of the timing chart shown in FIG. 8 is expressed for simplification of the drawing, and is different from the actual time. Further, the “Z-axis height” in FIG. 8 indicates a position (height position) of the wafer chuck support surface 72a of the Z-axis moving / rotating portion 72 in the Z-axis direction. Further, the “chuck height” in FIG. 8 refers to the height position of the wafer chuck 34 (specifically, the Z-axis direction of the wafer holding surface 34a) when the contact position described later is set as the reference position (0 point position). Position) is shown.

Hereinafter, in the present specification, when the wafer chuck 34 is moved toward the probe card 32, the height position of the wafer chuck 34 before each probe 36 of the probe card 32 comes into contact with the electrode pad of each chip of the wafer W. Is the "contact position", and the height position of the wafer chuck 34 when each probe 36 of the probe card 32 comes into contact with the electrode pad of each chip of the wafer W is set as the "contact position", and the probe card is used when inspecting the wafer W. The height position of the wafer chuck when each probe 36 of 32 comes into contact with the electrode pad of each chip of the wafer W in the overdrive state (appropriate overdrive amount of the probe card 32) is defined as the "final overdrive position", and the contact position. The height position of the wafer chuck 34 between the overdrive final position and the overdrive final position is referred to as an "overdrive intermediate position".

(Preliminary operation)
The pre-operation of the contact operation will be described.

First, as a preliminary operation of the contact operation, the alignment device 70 is moved to the measuring unit 16 to be inspected, and then the wafer chuck 34 is delivered to the alignment device 70 in a state of being positioned and fixed by a positioning and fixing device (not shown). .. Since the transfer operation of the wafer chuck 34 before the start of the contact operation is not a main part of the present invention, detailed description thereof will be omitted.

(Step S10: Wafer chuck fixing step)
After the wafer chuck 34 is delivered to the alignment device 70, as shown in FIG. 7A, the chuck fixing solenoid valve control unit 112 turns the chuck fixing solenoid valve 84 ON (open state) and moves / rotates the Z-axis. The wafer chuck 34 is attracted and fixed to the wafer chuck support surface 72a (see FIG. 4) of the portion 72 (time T1 in FIG. 8). At this time, by engaging the positioning pin 88 of the Z-axis moving / rotating portion 72 with the V groove of the V block 90 of the wafer chuck 34, the alignment device 70 and the wafer chuck 34 are relatively positioned.

After that, when the wafer W is supplied (loaded) to the wafer chuck 34 supported and fixed to the alignment device 70, the wafer adsorption solenoid valve control unit 110 turns on the wafer adsorption solenoid valve 46 (open state), and the wafer The wafer W is adsorbed and fixed to the holding surface 34a (see FIG. 4) (time T2 in FIG. 8).

(Step S12: Alignment step)
Next, the X-axis movement control unit 102, the Y-axis movement control unit 104, and the θ rotation control unit 108 are based on the results captured by the needle position detection camera and the wafer alignment camera under the control of the overall control unit 100. The X-axis drive motor 118, the Y-axis drive motor 120, and the rotary drive motor 124 are controlled to perform relative alignment between the wafer W held by the wafer chuck 34 and the probe card 32.

(Step S14: Shutter opening step)
Next, as shown in FIG. 7A, the shutter control unit 116 opens the shutter means 58 to open the communication passage 56 (time T3 in FIG. 8).

The shutter opening step may be executed at least before the ring-shaped seal member 48 comes into contact with the head stage 30 (see FIG. 7B) in the Z-axis raising step described later. For example, the shutter opening step may be performed between the wafer chuck fixing step and the alignment step, or may be performed before the wafer chuck fixing step. Further, the shutter opening step may be performed at the same time as the wafer chuck fixing step or the alignment step.

(Step S16: Z-axis rising step)
Next, as shown in FIGS. 7B and 7C, the Z-axis movement control unit 106 controls the Z-axis drive motor 122 to raise the Z-axis movement / rotation unit 72, thereby using the wafer chuck 34 as a probe card. Move toward 32 (time T4 to T5 in FIG. 8). Specifically, the wafer chuck 34 is raised so that the wafer chuck 34 moves from a predetermined height position (standby position) to a height position where the ring-shaped sealing member 48 contacts the head stage 30 (see FIG. 7B). Further, the wafer chuck 34 is raised so as to move to an overdrive intermediate position beyond the contact position (see FIG. 7C). As a result, each probe 36 of the probe card 32 comes into contact with the electrode pad of each chip of the wafer W in an overdrive state. The Z-axis raising step is a main part of the present invention, and details will be described later.

(Step S18: Shutter closing step)
Next, as shown in FIG. 7D, the shutter control unit 116 closes the shutter means 58 and shuts off the communication passage 56 (time T6 in FIG. 8). As a result, the internal space S formed between the wafer chuck 34 and the probe card 32 by the ring-shaped sealing member 48 becomes a non-communication state (sealed state) that does not communicate with the external space.

(Step S20: Decompression step)
Next, as shown in FIG. 7D, the suction control unit 114 controls the operation of the vacuum electropneumatic regulator 54 to start depressurization of the internal space S (time T7 in FIG. 8). At this time, the suction control unit 114 has an appropriate overdrive amount (appropriate OD position) of the probe card 32 when the wafer chuck 34 is released from being fixed by the suction port 80 (see FIG. 4) of the Z-axis moving / rotating unit 72. A target pressure is set so that the wafer chuck 34 rises up to, and the internal pressure of the internal space S is adjusted so as to reach the target pressure. The target pressure of the internal space S may be obtained empirically or experimentally, or may be obtained from a design value. For example, in order to determine the target pressure, the reaction force received from the probe 36 when the wafer chuck 34 rises to the appropriate overdrive amount of the probe card 32 (the reaction force when the probe 36 is crushed) and the probe card 32. It can be obtained from the total number of probes 36 provided in. If the total stylus pressure of the probe card 32 (total pressure received from the probe 36) is known, the negative pressure required by dividing by the area of the surface (adsorption surface) surrounded by the ring-shaped sealing member 48 is the target of the internal space S. Obtained as pressure. However, it is necessary to set the target pressure of the internal space S in consideration of the weight of the wafer chuck 34 and the reaction force caused by crushing the ring-shaped sealing member 48.

(Step S22: Judgment step)
Next, the suction control unit 114 determines whether or not the internal pressure (pressure value P1) of the internal space S has reached the set pressure (pressure value P2) set by the vacuum electropneumatic regulator 54. This determination is repeated until the internal pressure (pressure value P1) reaches the set pressure (pressure value P2), and when the set pressure (pressure value P2) is reached, the process proceeds to the next step S24. As a result, when the internal pressure of the internal space S stabilizes at the set pressure, the wafer chuck fixing release step (step S24) described later is performed. The internal pressure of the internal space S may be directly detected by, for example, a pressure sensor provided in the wafer chuck 34 or the head stage 30, or may be built in or connected to the vacuum electropneumatic regulator 54. It may be detected by a pressure sensor.

(Step S24: Wafer chuck fixing release step)
Next, as shown in FIG. 7E, the chuck fixing solenoid valve control unit 112 turns off the chuck fixing solenoid valve 84 (closed state), and the suction port 80 of the Z-axis moving / rotating unit 72 (see FIG. 4). The wafer chuck 34 is released from the fixing by (time T9 in FIG. 8).

At this time, since the internal pressure of the internal space S is adjusted to the set pressure by the vacuum electropneumatic regulator 54, when the fixing of the wafer chuck 34 by the Z-axis moving / rotating portion 72 is released, the wafer chuck 34 becomes the Z-axis. It separates from the moving / rotating portion 72 and rises to the final position of the overdrive (T9 to T10 in FIG. 8). As a result, the electrode pads and probe cards 32 of each chip of the wafer W to be inspected are not affected by the inclination of the wafer W and the array surface of the tip of the probe 36 and the variation of the tip position of the probe 36. The probe 36 is reliably contacted with a predetermined contact pressure.

As described above, in the present embodiment, the wafer chuck 34 is released from being fixed after the decompression of the internal space S is started, so that the wafer chuck 34 is not fixed to either side at the moment of switching between these steps. The stable state (free state) disappears, the transfer operation of the wafer chuck 34 can be performed stably, and good contact can be realized between the electrode pad on the wafer W and the probe 36. The control is realized by controlling the suction control unit 114 and the chuck fixing solenoid valve control unit 112 in cooperation with each other under the control of the overall control unit 100 that functions as the timing control means of the present invention.

Further, in the present embodiment, since the throttle valve 86 is provided in the suction path connecting the suction path 82 of the Z-axis moving / rotating portion 72 and the chuck fixing solenoid valve 84, the internal space S is depressurized. Even if the wafer chuck 34 is released from being fixed after the start of the operation, the negative pressure on the lower side (Z-axis moving / rotating portion 72 side) of the wafer chuck 34 is not suddenly lost. Therefore, the wafer chuck 34 is suddenly restrained from below (that is, the Z-axis moving / rotating portion 72) while being pulled from both the upper and lower sides (that is, both sides of the Z-axis moving / rotating portion 72 and the probe card 32). Since the fixing force (fixing force due to adsorption from the wafer) is not lost, the wafer chuck 34 does not suddenly move, and abnormal vibration and abnormal contact can be reduced. Therefore, it is possible to prevent the wafer chuck 34 from suddenly detaching from the Z-axis moving / rotating portion 72 when the wafer chuck fixing release step is performed, so that the transfer operation of the wafer chuck 34 is performed more stably. It becomes possible.

In this embodiment, as an example, a throttle valve 86 is provided in the suction path connecting the suction path 82 of the Z-axis moving / rotating portion 72 and the chuck fixing electromagnetic valve 84. A throttle valve 86 may be provided in the path connecting the suction port 80 of the shaft moving / rotating portion 72 and the suction device 44. For example, the throttle valve 86 may be provided in the suction path 82 of the Z-axis moving / rotating portion 72. May be provided.

(Step S26: Z-axis lowering step)
Next, as shown in FIG. 7F, the Z-axis movement control unit 106 controls the Z-axis drive motor 122 to lower the Z-axis movement / rotation unit 72 to a predetermined height position (standby position) (FIG. 7F). 8 hours T11 to T12).

As described above, when the wafer chuck 34 is delivered from the alignment device 70 (Z-axis moving / rotating portion 72) to the head stage 30 (probe card 32 side), each probe 36 of the probe card 32 has a uniform contact pressure. In the state of contact with the electrode pads of each chip of the wafer W, the wafer level inspection can be started. After that, a power supply and a test signal are supplied from the test head to each chip of the wafer W via each probe 36, and the signal output from each chip is detected to perform an electrical operation inspection.

After the wafer chuck 34 is handed over from the alignment device 70 (Z-axis moving / rotating unit 72) to the head stage 30 (probe card 32 side), the alignment device 70 moves to another measuring unit 16 and measures the wafer chuck 34. In the unit 16, the contact operation is performed in the same procedure, and the wafer level inspection is sequentially performed.

Next, the contact operation in the prober 10 according to the present embodiment will be described in detail.

(First operation example)
A first operation example of the contact operation in the prober 10 according to the present embodiment will be described with reference to FIG. FIG. 9 is a diagram (graph) showing a first operation example of the contact operation, and shows a temporal change in the height of the wafer chuck 34 (wafer holding surface 34a).

As shown in FIG. 9, in the first operation example, first, the Z-axis movement control unit 106 first moves the wafer chuck 34 from a predetermined standby position (for example, −500 μm) to a position immediately before contact (for example, −50 μm). It is moved at a moving speed (corresponding to the inclination of the straight line A1) (the straight line A1 portion).

Next, the Z-axis movement control unit 106 temporarily stops the wafer chuck 34 at the position immediately before the contact (straight line A2 portion).

Next, the Z-axis movement control unit 106 moves the wafer chuck 34 from the position immediately before the contact to the overdrive intermediate position (for example, +50 μm) beyond the contact position at a second movement speed (inclination of the straight line A3) slower than the first movement speed. (Equivalent to) (corresponding to straight line A3 part).

Here, for example, when the contact operation is performed by the vacuum suction method as in the prior art, it is difficult to sufficiently remove the oxide film on the electrode pad because the moving speed of the wafer chuck 34 is slow. On the other hand, in the present embodiment, the Z-axis moving / rotating unit 72 (Z-axis drive motor 122) performs a contact operation in which the probe 36 and the electrode pad are brought into contact with each other in an overdrive state, so that the probe 36 is formed on the electrode pad. The wafer chuck 34 can be moved toward the probe card 32 at a speed sufficiently faster than the speed required for removing the oxide film (the speed required for removing the oxide film). Further, the second moving speed when the wafer chuck 34 is moved by the Z-axis moving / rotating portion 72 is slower than the first moving speed to the position immediately before the contact as described above, and damages the wafer W and the probe 36. It is set to no speed (appropriate contact speed).

Next, when the wafer chuck 34 reaches the overdrive intermediate position, the Z-axis movement control unit 106 stops the movement of the wafer chuck 34 (straight line A4 portion).

Next, the suction control unit 114 moves the wafer chuck 34 from the overdrive intermediate position to the overdrive final position (for example, +100 μm) by controlling the operation of the vacuum electropneumatic regulator 54 to reduce the pressure in the internal space S. (Straight line A5 part).

In the present embodiment, as described above, the Z axis is at a timing later (second timing; time T9 in FIG. 8) than the timing at which decompression of the internal space S is started (first timing; time T7 in FIG. 8). The wafer chuck 34 is released from being fixed by the suction port 80 (see FIG. 4) of the moving / rotating portion 72. As a result, the unstable state (free state) in which the wafer chuck 34 is not fixed to either side is eliminated at the moment of switching between these steps, and the transfer operation of the wafer chuck 34 can be stably performed. The same applies to other operation examples described later.

According to the first operation example, the wafer chuck 34 is moved from the predetermined standby position to the position immediately before the contact at the first moving speed, the movement of the wafer chuck 34 is temporarily stopped, and then the wafer chuck 34 is contacted. The wafer is moved from the immediately preceding position to the intermediate position of the overdrive at a second moving speed faster than the first moving speed. At this time, since the wafer chuck 34 is moved by the Z-axis moving / rotating unit 72 (Z-axis drive motor 122), the moving distance and moving speed of the wafer chuck 34 can be accurately adjusted and formed on the electrode pad. It is also possible to secure the moving speed of the wafer chuck 34 required to remove the oxide film. This makes it possible to remove the oxide film formed on the electrode pad without damaging the wafer W. In addition, the throughput can be improved, vibration at the time of contact can be minimized, and the influence on other measuring units 16 during inspection can be reduced. Therefore, good contact can be achieved between the electrode pad on the wafer W and the probe 36.

(Second operation example)
A second operation example of the contact operation in the prober 10 according to the present embodiment will be described with reference to FIG. FIG. 10 is a diagram (graph) showing a second operation example of the contact operation.

As shown in FIG. 10, in the second operation example, the Z-axis movement control unit 106 moves the wafer chuck 34 to the position immediately before the contact (for example, −50 μm) at the first movement speed (corresponding to the inclination of the straight line B1). After that (straight line B1 portion), the moving speed of the wafer chuck 34 is changed without temporarily stopping the wafer chuck 34 at the position immediately before the contact, and the wafer chuck 34 is moved to the overdrive intermediate position (for example, +50 μm). It is moved at two moving speeds (corresponding to the inclination of the straight line B2) (the straight line B2 portion). Other operations are the same as in the first operation example.

In the first operation example described above, the wafer chuck 34 is temporarily stopped at the position immediately before the contact, but depending on various conditions of the contact operation in the prober 10 (for example, the distance between the position immediately before the contact and the contact position). May not have to temporarily stop the wafer chuck 34 at the position immediately before the contact. The second operation example assumes such a case, and since the operation of temporarily stopping the wafer chuck 34 before the contact height is not performed, the throughput is improved as compared with the first operation example. It becomes possible.

(Third operation example)
A third operation example of the contact operation in the prober 10 according to the present embodiment will be described with reference to FIG. FIG. 11 is a diagram (graph) showing a third operation example of the contact operation.

As shown in FIG. 11, in the third operation example, the Z-axis movement control unit 106 moves the wafer chuck 34 to the position immediately before the contact (for example, −50 μm) at the first movement speed (corresponding to the inclination of the straight line C1). After that (straight line C1 portion), the wafer chuck 34 is temporarily stopped at the position immediately before the contact (straight line C2 portion). After that, the wafer chuck 34 is moved from the position immediately before the contact to the overdrive intermediate position (for example, +50 μm) at a second moving speed (corresponding to the inclination of the straight line C3) slower than the first moving speed (corresponding to the inclination of the straight line C3). The wafer chuck 34 is temporarily stopped at a position during overdrive (straight line C4 portion). The operations up to this point are the same as in the first operation example.

In the third operation example, the Z-axis movement control unit 106 further moves the wafer chuck 34 from the overdrive intermediate position to the position immediately before the contact (straight line C5 portion). At this time, the moving speed of the wafer chuck 34 may be the same as the second moving speed, or may be different from the second moving speed. In the example shown in FIG. 11, the moving speed when the wafer chuck 34 is moved from the position in the middle of overdrive to the position immediately before the contact is the same as the second moving speed and the direction is opposite to that of the second moving speed.

Next, the Z-axis movement control unit 106 temporarily stops the wafer chuck 34 at the position immediately before the contact (straight line C6 portion), and then moves the wafer chuck 34 from the position immediately before the contact to the overdrive intermediate position (straight line C7). part). At this time, the moving speed of the wafer chuck 34 (corresponding to the inclination of the straight line C7) is the second moving speed (corresponding to the inclination of the straight line C3) when the wafer chuck 34 is first moved from the position immediately before the contact to the position in the middle of overdrive. Is set to the same size and orientation. The moving speed of the wafer chuck 34 may be at least higher than the speed required to remove the oxide film formed on the electrode pad (the speed required to remove the oxide film), and is the second moving speed. It may be different from the size.

Next, when the wafer chuck 34 reaches the overdrive intermediate position, the Z-axis movement control unit 106 stops the movement of the wafer chuck 34 (straight line C8 portion).

Next, the suction control unit 114 moves the wafer chuck 34 from the overdrive intermediate position to the overdrive final position (for example, +100 μm) by controlling the operation of the vacuum electropneumatic regulator 54 to reduce the pressure in the internal space S. (Straight line C9 part).

According to the third operation example, the same effect as that of the first operation example described above can be obtained, and the step of moving the wafer chuck 34 from the position immediately before the contact to the position in the middle of overdrive (Z-axis raising step) is repeated a plurality of times. As a result, a probe contact step (repeat contact step) is performed in which each probe 36 of the probe card 32 is repeatedly contacted with the electrode pads of each chip of the wafer W in an overdrive state a plurality of times. As a result, the effect of removing the oxide film formed on the electrode pad is increased, and the electrical contact reliability between the electrode pad on the wafer W and the probe 36 is improved.

In the third operation example, the step of moving the wafer chuck 34 from the position immediately before the contact to the position in the middle of overdrive (Z-axis raising step) is repeated twice, but the number of repetitions of the Z-axis raising step is particularly limited. Instead, the Z-axis ascending step may be repeated three or more times.

(Fourth operation example)
A fourth operation example of the contact operation in the prober 10 according to the present embodiment will be described with reference to FIG. FIG. 12 is a diagram (graph) showing a fourth operation example of the contact operation.

As shown in FIG. 12, in the fourth operation example, the Z-axis movement control unit 106 moves the wafer chuck 34 to the position immediately before the contact (for example, −50 μm) at the first movement speed (corresponding to the inclination of the straight line D1). After that (straight line D1 portion), the wafer chuck 34 is temporarily stopped at the position immediately before the contact (straight line D2 portion). The operations up to this point are the same as in the first operation example.

In the fourth operation example, the Z-axis movement control unit 106 further moves the wafer chuck 34 from the position immediately before the contact to the final overdrive position (for example, +100 μm) at the second movement speed (corresponding to the inclination of the straight line D3) (straight line). (D3 portion), when the wafer chuck 34 reaches the final position of overdrive, the movement of the wafer chuck 34 is stopped (straight line D4 portion).

Next, the suction control unit 114 controls the operation of the vacuum electropneumatic regulator 54 to reduce the pressure in the internal space S, so that the height position of the wafer chuck 34 is maintained at the final overdrive position. Is vacuum-sucked and held (straight line D5 portion).

According to the fourth operation example, the same effect as that of the first operation example described above can be obtained, and the wafer chuck 34 is overdriven from the position immediately before the contact by the Z-axis moving / rotating unit 72 (Z-axis drive motor 122) to the final position. Since it is moved to, the time required for the contact operation can be shortened as compared with the case where the wafer chuck 34 is moved from the overdrive intermediate position to the overdrive final position by depressurizing the internal space S, further improving the throughput. It becomes possible to plan.

(Fifth operation example)
A fifth operation example of the contact operation in the prober 10 according to the present embodiment will be described with reference to FIG. FIG. 13 is a diagram (graph) showing a fifth operation example of the contact operation. Further, FIG. 14 is a schematic view showing how the oxide film on the electrode pad is removed by the probe in the fifth operation example of the contact operation.

As shown in FIG. 13, in the fifth operation example, the Z-axis movement control unit 106 moves the wafer chuck 34 to the position immediately before the contact (for example, −50 μm) at the first movement speed (corresponding to the inclination of the straight line E1). After that (straight line E1 portion), the wafer chuck 34 is temporarily stopped at the position immediately before the contact (straight line E2 portion). The operations up to this point are the same as in the first operation example.

In the fifth operation example, the Z-axis movement control unit 106 further moves the wafer chuck 34 to the final overdrive position (for example, +100 μm) at a second movement speed (corresponding to the inclination of the straight line E3) slower than the first movement speed. (Line E3 portion), and when the wafer chuck 34 reaches the final position of overdrive, the movement of the wafer chuck 34 is stopped (straight line E4 portion).

Next, the Z-axis movement control unit 106 moves the wafer chuck 34 from the final overdrive position to the intermediate position of the overdrive (straight line E5 portion). At this time, the moving speed of the wafer chuck 34 has the same magnitude as the second moving speed and the direction is opposite to that of the second moving speed, but the moving speed may be different from the second moving speed.

Next, when the wafer chuck 34 reaches the overdrive intermediate position, the Z-axis movement control unit 106 stops the movement of the wafer chuck 34 (straight line E6 portion).

Next, the suction control unit 114 moves the wafer chuck 34 from the overdrive intermediate position to the overdrive final position (for example, +100 μm) by controlling the operation of the vacuum electropneumatic regulator 54 to reduce the pressure in the internal space S. (Straight line E7 part).

In the fifth operation example, the same effect as that of the first operation example described above can be obtained, and the wafer chuck 34 can be moved up and down while maintaining the overdrive state by the Z-axis moving / rotating unit 72 (Z-axis drive motor 122). Will be done. That is, since the probe 36 and the electrode pad reciprocate up and down the wafer chuck 34 at a height that does not separate from each other, the moving distance of the up and down movement of the wafer chuck 34 is shorter than that of the third operation example (repeat contact) described above. The contact operation can be efficiently performed in a short time, and the throughput can be improved.

Further, in the fifth operation example, it is preferable that the probe 36 is a cantilever type probe. For example, when the probe contact step (repeat contact step) of repeatedly contacting the wafer chuck 34 between the position immediately before contact and the position during overdrive is performed as in the third operation example described above, the oxide film is removed. Since the probe 36 comes into contact with the boundary between the region where the oxide film is removed and the region where the oxide film is not removed, the oxide film remains on the needle tip of the probe 36, and a part of the oxide becomes a residue and adheres to the needle tip. May be done. On the other hand, in the fifth operation example, by using the cantilever type probe as the probe 36, as shown in FIGS. 14A to 14E, the tip of the probe 36 becomes an electrode as the wafer chuck 34 moves. Since the surface of the pad P slides in the horizontal direction, the oxide film Q formed on the electrode pad P is scraped off, and the effect of removing the oxide film Q can be enhanced. Further, as shown in FIG. 14, since the wafer chuck 34 reciprocates up and down at a height at which the probe 36 and the electrode pad P are not separated from each other, the oxide film Q scraped off by the probe 36 is collected at both ends of the electrode pad P. Therefore, the residue of the oxide film Q on the probe contact surface of the electrode pad P can be eliminated, and the probe 36 can be brought into contact with the portion of the electrode pad P on the probe contact surface from which the oxide film Q has been removed. This makes it possible to improve the electrical contact reliability between the electrode pad on the wafer W and the probe 36.

(6th operation example)
A sixth operation example of the contact operation in the prober 10 according to the present embodiment will be described with reference to FIG. FIG. 15 is a diagram (graph) showing a sixth operation example of the contact operation.

As shown in FIG. 15, in the sixth operation example, the Z-axis movement control unit 106 moves the wafer chuck 34 to the position immediately before the contact (for example, −50 μm) at the first movement speed (corresponding to the inclination of the straight line F1). After that (straight line F1 portion), the wafer chuck 34 is temporarily stopped at the position immediately before the contact (straight line F2 portion). After that, the wafer chuck 34 is moved from the position immediately before the contact to the position in the middle of overdrive (for example, +50 μm) at a second moving speed (corresponding to the inclination of the straight line F3) slower than the first moving speed (corresponding to the inclination of the straight line F3). When the wafer chuck 34 reaches the position in the middle of overdrive, the movement of the wafer chuck 34 is stopped (straight line F4 portion). After that, the suction control unit 114 controls the operation of the vacuum electropneumatic regulator 54 to reduce the pressure in the internal space S, thereby moving the wafer chuck 34 to the final overdrive position (for example, +100 μm) (straight line F5 portion). The operations up to this point are the same as in the first operation example.

In the sixth operation example, the suction control unit 114 further stops the wafer chuck 34 at the final position of the overdrive (straight line F6 portion), and then moves the wafer chuck 34 to the intermediate position of the overdrive (straight line F7 portion). ). Then, after the wafer chuck 34 is temporarily stopped at a position in the middle of overdrive (straight line F8 portion), the wafer chuck 34 is moved to the final position of overdrive (straight line F9 portion). At this time, the vertical operation of the wafer chuck 34 is realized by changing the internal pressure of the internal space S by the vacuum electropneumatic regulator 54.

In the sixth operation example, the same effect as that of the first operation example described above can be obtained, and the wafer chuck 34 is moved up and down while maintaining the overdrive state by changing the internal pressure of the internal space S by the vacuum electropneumatic regulator 54. The operation is performed. That is, since the wafer chuck 34 reciprocates up and down at a height at which the probe 36 and the electrode pad do not separate from each other, the oxide films scraped off by the probe 36 are collected at both ends of the electrode pad as in the fifth operation example described above. The probe 36 can be brought into contact with the portion from which the oxide film has been removed. This makes it possible to improve the electrical contact reliability between the electrode pad on the wafer W and the probe 36.

As described above, in the contact operation in the prober 10 according to the present embodiment, the electrode pad and the probe 36 on the wafer W are moved by moving the wafer chuck 34 up and down (Z direction) by the Z-axis moving / rotating portion 72. The operation of contacting and is performed in the overdrive state. Since the Z-axis moving / rotating unit 72 is composed of at least a mechanical drive mechanism including a motor (Z-axis drive motor 122), it is possible to accurately adjust the moving distance, moving speed, etc. of the wafer chuck 34. is there. Further, the Z-axis moving / rotating unit 72 can move the wafer chuck 34 at a moving speed sufficiently faster than the contact operation by the vacuum suction method as in the prior art. Therefore, when the electrode pad on the wafer W and the probe 36 are brought into contact with each other, the oxide film (insulator) on the electrode pad can be removed by the contact of the probe 36, and the wafer W is not damaged. , Good contact can be achieved between the electrode pad on the wafer W and the probe 36.

Further, in the present embodiment, the Z-axis moving / rotating portion 72 is performed at a timing (second timing; time T9 in FIG. 8) later than the timing (first timing; time T7 in FIG. Since the wafer chuck 34 is released from being fixed by the suction port 80 (see FIG. 4), the wafer chuck 34 is not fixed to either side at the moment of switching between these steps (free state). It becomes possible to stably perform the transfer operation of the wafer chuck 34, and it is possible to realize good contact between the electrode pad on the wafer W and the probe 36.

Further, in the present embodiment, the shutter opening step (step S14) is performed at least before the ring-shaped sealing member 48 of the wafer chuck 34 is in contact with the head stage 30 (see FIG. 7B). That is, in the Z-axis raising step (step S16), from the state in which the ring-shaped sealing member 48 is in contact with the head stage 30 (see FIG. 7B) to the state in which the wafer chuck 34 is further raised (see FIG. 7C). Is in a state of communication (non-sealed state) in which the internal space S communicates with the external space via the communication passage 56.

Here, when the wafer chuck 34 is to be raised by the Z-axis moving / rotating portion 72 in a non-communication state (sealed state) in which the internal space S does not communicate with the external space, the internal space S is raised as the wafer chuck 34 is raised. The air inside is momentarily compressed to generate a strong reaction force, which causes the head stage 30 to vibrate, and the probe card 32 and the wafer W may come into contact with each other in an unintended manner. In this case, the probe card 32 and the wafer W may be damaged due to abnormal contact between the probe card 32 and the wafer W.

On the other hand, in the present embodiment, as described above, the wafer chuck 34 is raised by the Z-axis moving / rotating portion 72 in the communicating state (non-sealed state) in which the internal space S communicates with the external space. The wafer chuck 34 can be raised stably and efficiently without generating an unreasonable reaction force (reaction force for returning the wafer chuck 34 to its original position) when the 34 is raised, and the probe card 32 and the wafer W can be raised. Can be prevented from being damaged.

Further, in the present embodiment, since the throttle valve 86 for limiting the flow rate of gas is provided in the path connected to the suction port 80 of the Z-axis moving / rotating portion 72, the wafer chuck fixing release step (step S24). It is possible to prevent the wafer chuck 34 from suddenly detaching from the Z-axis moving / rotating portion 72 when the operation is performed, and the transfer operation of the wafer chuck 34 can be performed more stably.

The prober and probe contact methods according to the present invention have been described in detail above, but the present invention is not limited to the above examples, and various improvements and modifications may be made without departing from the gist of the present invention. Of course it is good.

10 ... prober, 12 ... measurement unit, 14 ... loader unit, 16 ... measurement unit, 18 ... load port, 20 ... wafer cassette, 22 ... operation panel, 24 ... transfer unit, 26 ... transfer arm, 30 ... head stage, 32 ... Probe card, 34 ... Wafer chuck, 34a ... Wafer holding surface, 36 ... Probe, 40 ... Suction port, 42 ... Suction path, 44 ... Suction device, 44 ... Suction device, 46 ... Wafer suction electromagnetic valve, 48 ... Ring Shape seal member, 48 ... ring-shaped seal member, 50 ... suction port, 52 ... suction path, 54 ... vacuum electropneumatic regulator, 56 ... communication path, 58 ... shutter means, 70 ... alignment device, 72 ... Z-axis movement / rotation Part, 72a ... Wafer chuck support surface, 74 ... X-axis moving table, 76 ... Y-axis moving table, 78 ... Ring-shaped sealing member, 78 ... Ring-shaped sealing member, 80 ... Suction port, 82 ... Suction path, 84 ... Chuck Electromagnetic valve for fixing, 86 ... throttle valve, 88 ... positioning pin, 90 ... V block, 92 ... Z-axis movement mechanism, 94 ... θ rotation mechanism, 100 ... overall control unit, 102 ... X-axis movement control unit, 104 ... Y Axis movement control unit, 106 ... Z-axis movement control unit, 108 ... θ rotation control unit, 110 ... Wafer suction electromagnetic valve control unit, 112 ... Chuck fixing electromagnetic valve control unit, 114 ... Suction control unit, 116 ... Shutter control Unit, 118 ... X-axis drive motor, 120 ... Y-axis drive motor, 122 ... Z-axis drive motor, 124 ... rotary drive motor, P ... electrode pad, Q ... oxide film, S ... internal space, W ... wafer

Claims (3)

A wafer chuck that holds the wafer and
A probe card provided so as to face the wafer chuck and having a probe at a position corresponding to each electrode pad of the wafer.
An annular sealing member provided on the wafer chuck and formed so as to surround the wafer held by the wafer chuck.
A mechanical lifting means for raising and lowering the wafer chuck fixed to the wafer chuck fixing portion and having a wafer chuck fixing portion for detachably fixing the wafer chuck.
A decompression means for reducing the pressure in the internal space formed by the probe card, the wafer chuck, and the seal member when the wafer chuck is moved toward the probe card by the mechanical elevating means.
An elevating control means that controls the mechanical elevating means to move the wafer chuck so that the probe is brought into contact with the electrode pad in an overdrive state.
A decompression control means that controls the decompression means so that the wafer chuck is attracted to the probe card by decompression of the internal space after the probe comes into contact with the electrode pad in an overdrive state.
With
In order to remove the oxide film on the electrode pad, the decompression control means controls the decompression means so that the wafer chuck is reciprocated up and down at a height at which the probe and the electrode pad are not separated.
Prober. The probe is a cantilever probe,
The prober according to claim 1 . A wafer chuck that holds the wafer and
A probe card provided so as to face the wafer chuck and having a probe at a position corresponding to each electrode pad of the wafer.
An annular sealing member provided on the wafer chuck and formed so as to surround the wafer held by the wafer chuck.
A mechanical lifting means for raising and lowering the wafer chuck fixed to the wafer chuck fixing portion and having a wafer chuck fixing portion for detachably fixing the wafer chuck.
A decompression means for reducing the pressure in the internal space formed by the probe card, the wafer chuck, and the seal member when the wafer chuck is moved toward the probe card by the mechanical elevating means.
A probe contact method in a prober equipped with
In order to remove the oxide film on the electrode pad, the oxide film removing step is provided in which the wafer chuck is reciprocated up and down at a height at which the probe and the electrode pad are not separated by the decompression means .
Probe contact method.

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